Ignition timer



Nov. 3, 1953 H. v. ELLIOTT 2,657,556

IGNITION TIMER Filed Oct. 26, 1949 /,v VENTOE Patented Nov. 3, 1953 IGNITION TIMER Harold V. Elliott, Anderson, Ind., assignor to General Motors Corporation, Detroit, Mich., a corporation of Delaware Application October 26, 1949, Serial No. 123,686

10 Claims.

This invention relates to ignition timers having speed responsive means for adjusting the annular location of the timer cam with respect to the engin driven shaft which operates the cam. The speed responsive means comprises a plate connected with the engine driven shaft of the timer and supporting weights which move out against the action of springs to turn the timer cam relative to the driving shaft. The timer cam is journaled on an extension of the drive shaft and is connected with a cam plate with which th weights engage. A cover plate attached to the plates supporting the weights retains the weights and the cam plates in location.

An object of the invention is to facilitate the attachment of the cover plate to the weight plate. This is accomplished by a construction of the cover plate and of the weight plate which provides for a snap-on connection.

Further objects and advantages of the present invention will be apparent from the following description, reference being had to the accompanying drawing, wherein a preferred embodiment of the present invention is clearly shown.

In the drawing:

Fig. 1 is a plan view of the ignition timer with the distributor cap removed.

Fig. 2 is a sectional view of the ignition timer and distributor on line 2-2 of Fig. 1.

Fig. 3 is a plan view of the assembly of timer cam, speed responsive device and cover therefor.

Fig. l a sectional view on line t-4 of Fig. 2.

Fig. 5 is a sectional view of the cover on line 5-5 of 3.

Fig. 6 is a fragmentary, sectional View of the cover on line 6-5 of Fig.3.

Fig. '7 is a sectional View of the cover on line 1-1 of Fig. 3.

Fig. 8 is a side view of the cover looking in the direction of arrow ii of Fig. 3.

Referring to Figs. 1 and 2, a housing If! supports a breaker plate II attached to the housing by screws l2. Plate II supports a bracket it which carries a stationary contact !4 engag able with. a movable contact I5 carried by circuit breaker lever Hi journaled on a pivot post I? and insulated therefrom, said post being attached to the plate I I and providing a pivot for the bracket I3 which is adjustable by the turning of a slotted disc I8 attached to an eccentric shank l5 pivoted on plate I I and disc I8 is received by a slot 20 of bracket This adjustment varies the location of a rubbing block 2! attached to lever I6 relative to the ignition timer cam 22 against which the block is urged by leaf spring 23 attached to lever IS at one end and at the other connected with a terminal 24 insulatingly supported by housing I0 and connected also by a wire 25 with one foil of a condenser, the other foil of which is connected with a condenser enclosing case 26 attached to plate II. Bracket It is maintained in adjusted position by the tightening of a screw 2'! passing through an arcuate slot 28 in bracket I3 and threaded into the plate I I.

Cam 22 is drivingly connected with a distributor rotor to having a segment 3I for distributing sparking impulses to distributor posts 32 from a center button 33 connected with an ignition coil secondary winding and engaged by a contact on the end of a leaf spring 34 attached to the segment 3|. The center button 33 and the post 32 are carried by a non-conducting distributor cap supported by the housing Ill.

The cam 22 is journaled on the extension 45 (Fig. l) of a driving shaft 41 rotatably supported by the housing It. Shaft 4! is connected with a weight plate 42 supporting weights 43 pivoted on studs 44 carried by the plate 42 and sliding on bosses 45 integral with plate 42. Weights 43 have arms 43a for engaging earns 46 provided by a cam plate attached to the tubular extension 48 of cam 22. Plate ll carries studs 49 connected by springs 55 with studs 56 whereby the weights 43 and cam plate 47 are urged into the normal position shown in Fig. 4. This is the arrangement of parts for a distributor whose cam rotates clockwise. As speed increases, weights 53 move outwardly against the action of springs 55 to eiiect clockwise rotation of plate 5'! and cam 22 in order to advance the timing of the ignition.

The weights at and the plate ii are retained upon the plate at by a cover 5| having openings 52 and 53 for receiving the cam 22, studs 4t and 39 and springs 55 which connect these studs. Plate 5! has two arcuate flanges 55 each provided with an arcuate bead 55 and each having a detent 55 adapted to be received by a notch 57! in plate 52. The cover 5| provides four stops 58. Each flange 5 is cut partially across at 55a, thus separating the shorter part of the flange which provides the detent 55 from the longer part of the flange.

The cover 5i is assembled with the plate 42 by holding the cover 5! approximately parallel with the plate and the detents 55 approximately in alignment with the notches 5'! of the plate while pressing the cover against the plate longer portions of the flanges 54 which provide the beads 55 bear resiliently against the edges of the plate 42.

The cover i does not turn relative to plate 42 which is subjected to torsional vibrationssince the detents 5G engage the notches 51 of the plate. The cover 5! remains assembled with the plate 42 although the timer may be subjected to up and down vibrations. If one were to grasp the shaft 4! in one hand before assembly in the timer housing l0, and were to grasp the cover 5! in the other hand and pull it in a direction away from the plate 42, the central part of the cover would be flexed away from the plate but the cover would not come loose from the plate because, the flanges 55 would grip the plate all the more firmly. While the assembly of shaft 4i, plate t2, cam 22 and cover 51 is disassembled from the housing iii, the cover 5| can be removed from the plate42 by pushing against the edges of the flanges 54 with pressure sufficient to cause the flanges 54 and their heads 55' to spring out around the edges of the plate. Obviously, in service, the cover 5! is not subjected to the application of any forces against the lower edges of the cover flanges 54. Therefore the cover 5! re mains assembled with the plate 42.

While the embodiment of the present invention as herein disclosed, constitutes a preferred form, it is to be understood that other forms might be adopted.

What is claimed is as follows:

1. In an ignition timer, the combination comprising a shaft, a weight plate attached thereto, a timer cam journaled on the shaft, means transmitting motion from the shaft to the cam and including weights-pivoted on the plate and providing levers, and a plate attached to .the cam and providing cams'engaged by said levers and a weight and cam plate retainer comprising a sheet metal plate through which the .timer'cam extends and having resilient flanges, said flanges being constructed to fit over the edge of the weight plate and having detents to provide retaining lugs cooperating with said weight plate to hold the retainer plate thereupon.

2. In an ignition timer, the combination comprising a shaft, 2. weight plate attached thereto, a timer cam journaled on the shaft, means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing levers, and a plate attached'to the cam and providing cams engaged by said levers, and a weight and cam plate .retainercomprising a sheet metal plate through which the timer cam extends and providing resilient flanges adapted to bear against edges of the weight plate and certain portions of these flanges providing internal beads for engaging the underside of the Weight plate and other flange portions providing detents for engaging in notches provided by the weight plate.

3. In an ignition timer, the combination comprising, a shaft; a weight plate attached to the shaft; a timer cam journalled on the shaft;

means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing levers; a plate attached to the cam and providing cams engaged by the levers; and a weight and a cam plate retainer comprising a sheet metal plate through which the timer cam extends and having oppositely disposed flanges, said flanges providing means for engaging the under side of the weight plate for locking the retainer to the weight plate and said flanges also providing additional means cooperating with notch provisions provided by the weight plate to prevent the retainer from turning relativetoi theweight plate.

4...In anignition timer, the combination comprising, a shaft; a weight plate attached to the shaft; a timer oamjournaled on the shaft; means transmitting motion from the shaft to the cam andincluding weights pivoted on the plate and providing levers; a plate attached to the cam and providing cams engaged by the levers; and a weight and. a cam plate retainer comprising a sheet metal plate'through which the timer cam extends and having a plurality of spacedresil lent arcuate flanges'extending generally axially ofjsaid retainer plate; and means for locking the retainer plate to the weight plate including circumferentially spaced struck in portions from the flanges.

5. Inantignition timer, the combination com prising, a shaft; a weight plate attached to the shaft; a timer cam journaled on the shaft; means transmitting motion from the shaft to the cam and including weights pivotedion the plate and providing levers; a plate attached to thecam andprovidingzcams engaged by the levers; and a weight and a cam-plateretainer comprising a sheet metal plate through which the timer. cam extends and having a plurality of spaced resilient arcuate flanges extending generally axially of said retainer plate; circumferential detents formed in the flangesadapted to engage the underside of the weight plate for locking the retainer'to the weight plate against accidental removalof the retainer plate; andadditional de tents formed in the flanges cooperating with means on the weightplate for preventing the re tainer plate from turning relative to the weight plate.

6. In an ignitionv timer, the combination comprising, a shaft; a weightplate attached to the shaft; a timer cam iournalled on the shaft; means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing levers; a plate attached to the cam and providing cams engaged by the levers; and a weight and a cam plate retainer comprising .a sheet metal plate through which the timer cam extends and having resilient flanges adapted to receive between them and yieldingly grip the periphery of the weight plate, at least one'of said flanges having means to interlock with the plate toprevent accidental removal of theretainer andmeans on at least one of the flanges cooperating with means provided by the plate to prevent rotation of the retainer relative to the weight plate, said flanges being yieldable so as to permit same to yield during assembly -of the retainer with said weight plate and snap into said interlocking relation.

'7. In an .ignitiontimer, the combination comprising, a shaft; a weight plate attached to the shaft; a timer cam iournaled on the shaft; means transmitting motion'from the shaft to the cam and including weights pivoted on the plate and providing levers; a plate attached to the cam and providing cams engaged by the levers; and a weight and a cam plate retainer comprising a sheet metal plate through which the timer cam extends and having holding means whereby the plate and retainer may be connected together against axial and turning movements solely by relative movement, said holding means including recesses in the plate and a plurality of projection means provided on the flanges, certain of the projection means being constructed and arranged to fit in the recesses of the plate to prevent the retainer from turning relative to the plate while the other projection means are positioned below the plate to hold yieldingly the retainer against accidental removal from the weight plate; and stop means provided by flanges adapted to engage the plate to limit the axial movement of the retainer plate as it is being connected with weight plate.

8. In an ignition timer, the combination comprising a shaft; a weight plate attached thereto, a timer cam journalled on the shaft; means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing arms; a plate attached to the cam and providing cams engaged by the arms; and a retainer consisting of a perforated plate through which the cam extends, said plate having oppositely disposed flexible flanges constructed to fit over the edge of the weight plate, portions of said flanges being dented inwardly to provide retainer lugs cooperating with the underside of said weight plate to hold the retainer thereon.

9. In an ignition timer, the combination comprising a shaft; a weight plate attached thereto, a timer cam journalled on the shaft; means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing arms; a plate attached to the cam and providing cams engaged by the arms; a retainer plate having an opening through which the cam extends, said retainer plate having resilient axially extending flanges for receiving the weight plate; said flanges having lugs extending inwardly therefrom for engaging the weight plate removably to hold the retainer on said weight late.

10. In an ignition timer, the combination comprising a shaft; a weight plate attached thereto, a timer cam journalled on the shaft; means transmitting motion from the shaft to the cam and including weights pivoted on the plate and providing arms; a plate attached to the cam and providing cams engaged by the arms; and a retainer plate having an opening through which the cam extends, said plate having oppositely disposed flexible flanges constructed to fit over the edge of the weight plate, said flanges having lugs extending therefrom for engaging the weight plate to preclude accidental removal of the retainer, at least one of said flanges having an additional lug extending therefrom cooperating with means provided by the weight plate to prevent relative rotational movement of said retainer with respect to said weight plate when said retainer is assembled to said weight plate.

HAROLD V. ELLIOTT.

Name Date Hartzell et a1 Oct. 29, 1940 Number 

